Bronchodilators are the mainstay of current management of COPD, and the major recent advances have been in the development of long-acting bron-chodilators. Tiotropium bromide is a very promising new anticholinergic drug that has a very long duration of action. It has a high affinity and dissociates very slowly from M1 and M3-muscarinic receptors in the human lung, and it produces long-term blockade of cholinergic neural bronchoconstriction in human airway smooth muscle. However, its effects on acetylcholine release are short-lived, confirming functional selectivity for M3-receptors compared to M2-receptors. In studies of patients with COPD, tiotropium bromide gives prolonged bronchodilatation, lasting over 24h [20,21]. This suggests that tiotropium bromide will be suitable for once-daily dosing, and it is now in advanced clinical trials as a once-daily dry powder inhalation.
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If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.